Definition
A.Hepatitis C is an inflammation of the liver caused by the hepatitis C virus (HCV). HCV has signs and symptoms often undistinguishable from those of hepatitis A or B (HAV or HBV). The disease tends to be asymptomatic to mild and has an insidious onset. Acute fulminate infection is rare. The major feature of HCV is its propensity to become chronic.
B.Multiple (6) HCV genotypes and subtypes exist. It is possible for a person to be infected with more than one genotype. The genotype is a major factor in the effectiveness of the patient’s response to therapy.
C.The development of chronic hepatitis and its complications increase with several factors, including older age at acquisition, HBV coinfection, HIV coinfection, excessive alcohol consumption, and male gender.
D.HCV is the leading cause of nonalcoholic hepatic failure and cirrhosis, and the cause of 90% of posttransfusion hepatitis. Primary hepatocellular carcinoma (HCC) also occurs in these patients.
E.No vaccine for hepatitis C is available, therefore prevention of HCV depends on reducing the risk of exposure.
F.The Council of State and Territorial Epidemiologists (CSTE) Position Statements for Acute Hepatitis C :
1.Clinical criteria for acute HCV:
a.An illness with discrete onset of any sign or symptom consistent with acute viral hepatitis (e.g., fever, headache, malaise, anorexia, nausea, vomiting, diarrhea, and abdominal pain).
AND
i.Jaundice
OR
ii.A peak elevated serum ALT level greater than 200 IU/L during the period of acute illness.
2.Laboratory criteria for acute HCV:
a.A positive test for anti-HCV.
b.HCVdetection test:
i.Nucleic acid testing (NAT) for HCV RNA positive (including qualitative, quantitative, or genotype testing).
ii.A positive test indicating presence of HCV antigen(s).
3.Criteria to distinguish a new case from an existing case of acute HCV:
a.A new acute case is an incident acute hepatitis C case that meets the case criteria for acute hepatitis C and has not previously been reported.
b.A new probable acute case may be reclassified as a confirmed acute case if a positive NAT for HCV RNA or a positive HCV antigen(s) test is reported within the same year.
c.A confirmed acute case may be classified as a confirmed chronic case if a positive NAT for HCV RNA or a positive HCV antigen is reported one year or longer after acute case onset.
d.A confirmed acute case may not be reported as a probable chronic case (i.e., HCV antibody positive, but with an unknown HCV RNA NAT or antigen status).
4.Case classification for acute HCV:
a.Probable:
i.A case that meets clinical criteria and has a positive anti-HCV antibody test, but has no reports of a positive HCV NAT or positive HCV antigen tests
AND
ii.Does not have test conversion within 12 months or has no report of test conversion.
b.Confirmed:
i.A case that meets clinical criteria and has a positive HCV detection test (HCV NAT or HCV antigen)
OR
ii.A documented negative HCV antibody, HCV antigen, or NAT laboratory test result followed within 12 months by a positive result of any of these tests (test conversion).
G.The Council of State and Territorial Epidemiologists (CSTE) Position Statements for Chronic Hepatitis C:
1.Clinical criteria for chronic HCV:
a.No available evidence of clinical and relevant laboratory information indicative of acute infection (as noted earlier).
b.Most HCV-infected persons are asymptomatic; however, many have CLD, which can range from mild to severe.
2.Laboratory criteria for diagnosis of chronic HCV:
a.A positive test for anti-HCV.
b.HCV detection test for acute HCV:
i.NAT for HCV RNA positive (including qualitative, quantitative, or genotype testing.
ii.A positive test indicating presence of HCV antigen(s).
3.Criteria to distinguish a new case from an existing case of chronic HCV:
a.A new chronic case is an incident chronic hepatitis C case that meets the case criteria for chronic hepatitis C and has not previously been reported.
b.A confirmed acute case may not be reported as a probable chronic case (i.e., HCV antibody positive, but with an unknown HCV RNA NAT or antigen status).
4.The 2016 case classification for chronic HCV:
a.Probable:
i.A case that does not meet clinical criteria or has no report of clinical criteria.
AND
ii.Does not have test conversion within 12 months or has no report of test conversion.
AND
iii.Has a positive anti-HCV antibody test, but no report of a positive HCV NAT or positive HCV antigen test.
b.Confirmed:
i.A case that does not meet clinical criteria or has no report of clinical criteria.
AND
ii.Does not have test conversion within 12 months or has no report of test conversion.
AND
iii.Has a positive HCV NAT or HCV antigen test.
Incidence
A.The World Health Organization (WHO) estimates that more than 185 million individuals are chronically infected with HCV worldwide.
B.Of every 100 people infected with HCV, approximately:
1.75 to 85 will go on to develop chronic infection.
2.10 to 20 will go on to develop cirrhosis over a period of 20 to 30 years.
3.Rates of progression to cirrhosis are increased in the presence of a variety of factors: males more than females, age greater than 50 years, alcohol, nonalcoholic fatty liver disease (NAFLD), HBV or HIV coinfection, immunosuppressive therapy.
C.Among patients with cirrhosis, there is:
1.1% to 5% annual risk of HCC.
2.36% annual risk of hepatitic decompensation, for which the risk of death in the following year is 15% to 20%.
D.Approximately 15% to 25% of people clear the HCV virus without treatment and do not develop chronic infection. Although they are no longer infected, they will still test positive for antibodies to
HCV (anti-HCV):
1.Predictors of spontaneous clearance include jaundice, elevated alanine transaminase (ALT) level, hepatitis B surface antigen (HBsAg) positivity, female sex, younger age, HCV genotype 1, and host genetic polymorphisms, most notably those near the IL28B gene.
E.HCV infection becomes chronic in approximately 75% to 85% of cases. A person infected with HCV mounts an immune response to the virus, but replication of the virus during infection can result in changes that evade the immune response. This may explain how the virus establishes and maintains chronic infection.
F.Seroprevalence rates among individuals vary according to their associated risk factors. The highest rates occur in persons with large or repeated direct percutaneous exposure to blood or blood products, such as intravenous (IV) drug users and patients with hemophilia who have received multiple blood transfusions.
G.Seroprevalence among pregnant women in the United States has been estimated at 1% to 2%. Maternal–fetal (vertical) transmission only ranges from 3% to 10%. Risk for transmission is highest among women with a high viral load at delivery. Maternal coinfection with HIV has been associated with increased risk of perinatal transmission of HCV RNA.
H.Serum anti-HCV antibody and HCV RNA have been detected in colostrum. However, although only a limited number of patients have been studied, the rate of transmission among breastfed infants is the same as among bottle-fed infants.
Pathogenesis
A.HCV is a small, single-stranded RNA virus with a lipid envelope and is a member of the Flavivirus family. It is a bloodborne virus and the most common modes of infection are through exposure to small quantities of blood injection drug use, unsafe injection practices, and transfusion of unscreened blood and blood products.
B.The WHO also notes that one of the most common transmissions is in the reuse or inadequate sterilization of medical equipment, especially syringes and needles in healthcare settings.
C.Sexual transmission of HCV is uncommon except with high-risk behavior.
D.The incubation period averages 6 to 7 weeks, with a range of 2 weeks to 6 months. The time from exposure to the development of viremia generally is 1 to 2 weeks.
Predisposing Factors
All people with HCV-RNA in their blood are considered to be infectious. The following groups are at high risk for HCV infection and should be tested:
A.IV drug users who have shared needles.
B.Intranasal cocaine users, presumably resulting from epistaxis and shared equipment.
C.Hemophiliacs, hemodialysis patients, and those who received blood transfusions before 1992.
D.Recipients of solid organ transplants prior to 1992.
E.Healthcare workers with percutaneous exposures.
F.Individuals with multiple sexual partners.
G.Transmission among contacts living with infected persons may occur with percutaneous or mucosal exposure to blood.
H.Infants of infected mothers, by vertical transmission.
I.HCV is more common in males than females.
J.Tattooing, body piercing, and acupuncture with unsterile equipment.
K.HIV.
L.Incarceration.
Common Complaints
A.Chronic HCV—asymptomatic unless there is progressive inflammation and complications from cirrhosis.
B.Malaise.
C.Anorexia.
D.Nausea.
E.Myalgia.
F.Fever.
G.Abdominal pain.
Other Signs and Symptoms
A.Jaundice (occurs in fewer than 20% of patients).
B.Hepatomegaly is present in one third of patients with an acute infection.
C.Ascites.
D.Spider nevi.
E.Dark urine.
F.Clay-colored stools.
Subjective Data
A.Review duration, onset, and severity of symptoms.
B.Ask the patient about other family members and sexual contacts with similar symptoms.
C.Review family history of hepatocellular carcinoma (HCC).
D.Review the patient’s history of blood transfusions, tattoos, incarceration, IV drug use, and alcohol abuse.
E.Ask the patient about occupational exposure to blood and bodily secretions.
F.Ask about high-risk sexual practices.
G.Inquire about recent international travel.
H.Establish the patient’s usual weight; note amount of any weight lost and over what length of time.
I.Review for a history of variceal bleeding.
J.Ask if the patient has been treated for any type of hepatitis:
1.How long ago was the patient treated?
2.Did the patient complete therapy? If not, why?
3.What was the patient’s response to therapy (i.e. non-responder, relapser, etc.)?
K.Has the patient had any testing for cirrhosis/liver biopsy? What testing and when?
L.Review HIV status.
Physical Examination
A.Check temperature (acute infection), pulse, respirations, blood pressure (BP), height and weight to calculate body mass index (BMI).
B.Inspect:
1.Observe general appearance, muscle wasting, edema, and demeanor. Administer a depression self-assessment tool at each visit when on HCV therapy.
2.Inspect the skin for jaundice, rash, dehydration, palmar erythema, excoriations, spider nevi, and tattoos/piercings.
3.Inspect the eyes for yellow sclera.
4.Inspect mucous membranes and nail beds for clubbing and cyanosis.
5.Inspect for gynecomastia and small testes.
C.Auscultate:
1.Auscultate lung fields and heart.
2.Auscultate all quadrants of the abdomen and evaluate for abdominal bruit.
D.Percuss the abdomen.
E.Palpate:
1.Palpate all quadrants of the abdomen for masses, liver enlargement or tenderness, characteristics of cirrhosis, and hepatosplenomegaly, which occurs in about 10% of cases.
2.Palpate the lymph nodes for lymphadenopathy and enlarged parotid.
Diagnostic Tests
A.Complete blood count (CBC) with platelets.